<template>
  <div id="app">
    <router-view/>
  </div>
</template>

<script>
export default {
  name: 'app',
   created() {
    //在页面加载时读取sessionStorage里的状态信息
    if (sessionStorage.getItem('store') ) {
      this.$store.replaceState(Object.assign({}, this.$store.state,JSON.parse(sessionStorage.getItem('store'))))
    } 

    //在页面刷新时将vuex里的信息保存到sessionStorage里
    window.addEventListener('beforeunload',()=>{
      sessionStorage.setItem('store', JSON.stringify(this.$store.state))
    })
  }
}
</script>
<style lang="scss">
</style>


